Machine for folding flexible sheets



Jan. 18, 1955 P. H. DIXON EI'AL MACHINE FOR FOLDING FLEXIBLE SHEETS a Sheets-Sheet 1 Filed Jan. 9, 1951 Y 3 W i w c l m :9 paw P. H. DIXON ETAL MACHINE FOR FOLDING FLEXIBLE SHEETS Jan. 18, 1955 6 Sheets-Sheet 2 Filed Jan. 9, 1951 Jan. 18, 1955 P. H. DIXON ETAL 2,699,936

MACHINE FOR FOLDING FLEXIBLE SHEETS Filed Jan. 9, 1951 6 Sheets-Sheet 5 U-r-rommav/ Jan. 18, 1955 P. H. DIXON ETAL 2,699,936

MACHINE FOR FOLDING FLEXIBLE SHEETS Filed Jan. 9, 1951 6 Sheets-Sheet 4 94- 9S E3 12 8\ R ponuJ- 34. DLxon Q03 Q4o ORNEIY/ Jan. 18, 1955 P. H. DIXON ETAL 2,699,936

MACHINE FOR FOLDING FLEXIBLE SHEETS Filed Jan. 9, 1951 6 Sheets-Sheet 5 a ll lymml G mad 4 paul HlDLxom Q0 QM? Q-(ggJ Jan. 18, 1955 P. H. DIXON ETAL 2,699,936

MACHINE FOR. FOLDING FLEXIBLE SHEETS.

Filed Jan. 9, 1951 6 Sheets-Sheet 6 Egg-IS TTORNEV United States PatentO MACHINE FOR FOLDING FLEXIBLE SHEETS Paul H. Dixon and Roy W. Hays, Rockford, Ill., asssignors to Southern Handkerchief Manufacturing Company, Greenville, S. C., a corporation of South Carolina Application January 9, 1951, Serial No. 205,124

11 Claims. (Cl. 270-84) This invention relates to a method and machine for folding a flexible sheet such as a handkerchief first along spaced parallel lines to form an accordion pleated strip and then folding the strip longitudinally along spaced parallel lines to produce a compact package.

The general object is to provide a novel method of the above character by which the successive folding and transferring operations may be effected automatically and by simple mechanical means while retaining pos tive control over the sheet at all times to insure uniformity in the final package.

A more detailed object is to form the folded package in a continuous succession of perpendicular movements of a series of endwise movable blades each coacting with a holder by which the folded strip is gripped and positioned for proper engagement by the next blade.

Another object is to provide a novel method and apparatus for accordion pleating the flexible sheet.

A further object is to provide a novel apparatus by which a flexible strip may be folded lengthwise upon itself and, as an incident to such folding, both positioned accurately for the formation of a subsequent fold in the strip and transferred out of the folding mechanism into a holder in which the next fold is initiated.

Still another object is to fold the strip longitudinally upon itself by engaging an intermediate portion of the strip and forcing the same between two parallel walls which are spaced apart to receive the folded strip and retain the same frictionally in a proper position preparatory to another folding operation.

Still another object is to facilitate the formation of an additional fold in a folded strip and prevent loosening of its other folds by bending a folded end portion of the strip along the line of the fold to be formed prior to forcing the strip through a slot.

The invention also resides in the novel construction of certain of the folding mechanisms and their arrangement relative to each other to facilitate transfer of the partially folded strip to a succeeding folding mechanism by a continuation of the motion by which the previous fold is formed.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which Figures 1 through 8 are diagrammatic views showing the successive steps of folding a sheet of flexible material in a machine embodyingthe novelfeatures of the present invention.

Fig. 9 is a sectional view taken along the line 99 of Fig. 12.

Fig. 10 is an enlarged sectional view of one folding mechanism taken along the line 10-10 of Fig. 12 with the parts in a different position.

Fig. 11 is a fragmentary perspective view of the folding mechanism shown in Fig. 10.

Fig. 12 is a sectional view taken from the front of the machine along the line 1212 of Fig. 9.

Fig. 13 is a fragmentary sectional view taken along the line 1313 of Fig. 9.

Fig. 14 is a fragmentary perspective view showing a part of the mechanism of Fig. 11 and its relation to other folding mechanisms.

Fig. 15 is an elevational view showing the rear of the machine with a portion of the casing removed.

In general, the improved method involves first folding 2,699,936 Patented Jan. 18, 1955 "ice the sheet 11 (Fig. 1) back and forth zig-Zag fashion along longitudinally spaced parallel lines 15 to accordion pleat the sheet and from an elongated strip 16 of uniform Width as shown in Fig. 2. While the strip is still held in the pleating mechanism 17 (Figs. 9, l0, and 11) it is engaged intermediate its ends by the end of a blade 19 of the first folding mechanism 18 (Fig. 12) and forced laterally to form a fold 20 and bring opposite end portions against each other as shown in Fig. 3 with the ends 30 and 30a of the strip 16 spaced from each other. While the shortened strip 21 is still held straight in the mechanism 18, the blade 22 of the second folding mechanism 23 (Figs. 12 and 15) moves perpendicular to the motion of the first folding blade and, after engaging the strip near its free ends, forces the same laterally to form a fold 24 with the short end 26 of the strip lying against the longer end portion 27. After the folded end is turned through a quarter revolution as shown in Fig. 5, the blade 28 of a third folding mechanism 29 (Fig. 12) moves perpendicular to the motion of the second blade 22 and alongside the folded end portion 26 to engagethe shortened strip adjacent the end 30 and force a fold 31 in the strip which then comprises a short doubled end portion 32 lying alongside the longer remaining portion 27 of the strip 21 as shown in Fig. 6 and having a length substantially equal to that of such remaining portion. By the action of a blade 33, the shortened strip (Fig. 6) is doubled upon itself in a fourth folding mechanism 34 (Fig. 12) to bring the folds 20 and 31 adjacent each other and form the final package 10.

The blade 19 moves at right angles to the motion of the elements of the pleating mechanism 17 and pushes the fold 20 into a holder 35 (Fig. 3) by which the folded end portion of the shortened strip 21 is gripped frictionally and held in the proper position for starting of the next fold by advance of the blade 22. In a similar way, the successively acting blades 22, 28, and 33 move at right angles to the previously acting blade and push the fold into holders 36, 37, and 38 by which the folded strip is positioned for the next operation.

The pleating mechanism 17, the four folding mechanisms 18, 23, 29, and 34, and a mechanism for delivering successive unfolded sheets to the pleating mechanism are mounted on a suitable frame 40 and the movable parts thereof are actuated in accurately timed relation from a continuously rotated drive shaft 41 journaled on the frame. Herein, the drive shaft is connected by beveled gears 39 to a cam shaft 45 which is rotatably mounted on one side wall of the frame and is connected to the various mechanisms to actuate each of the latter once during every revolution of the cam shaft.

The accordion pleating mechanism 17 (see Figs. 9, 10, and 11) for forming the first folds 15 comprises generally two sets of laterally spaced parallel plates 42 and 43 which are staggered relative to each other and are relatively movable edgewise into overlapping relation from retracted positions on opposite sides of the sheet 11 while the latter is supported in a predetermined position between the sets of plates as shown in Fig. 9. During such movement of the plates, the sheet is forced around the ends of adjacent plates and threaded back and forth zig-zag fashion between the latter as shown in Fig. 10. In the present instance, the sheet is supported with one end portion 44 thereof suspended in a vertical plane indicated in Fig. 9 disposed between the two sets of plates which lie in vertically spaced horizontal planes. Each set comprises three plates and the plates 42 of one set are mounted on the frame 40 for reciprocation horizontally back and forth between a retracted position on one side of the vertical plane of the suspended end portion 44 and an advanced or overlapping position (see Fig. 10) in between the plates 43 of the other set which are stationarily mounted on the frame on the opposite side of the vertical plane.

In this instance, the lowermost one of the fixed plates 43 is one end portion of a heavy sheet 46 of metal spanning and supported on two horizontal frame members 47 (Fig. 12) extending along and secured as by bolts to the upper ends of two parallel side walls of the frame 40. The upper two fixed plates are generally rectangular in shape and project rigidly and toward the front of the machine in cantilever position from a stationary horizontal block 48 (Fig. 9) supported on the lowermost plate. At their free ends, the upper fixed plates terminate in parallel straight edges 49 lying in a vertical plane parallel to the vertical plane in which the sheet end portion 44 is suspended.

The reciprocable or movable plates 42 are disposed toward the front of the machine from the fixed plates 43 and project inwardly toward the latter and rigidly in cantilever fashion from a movable block 50 with their free ends terminating in straight edges 51 parallel to the fixed plate edges 49 and also disposed in a vertical plane so that the adjacent folds 15 formed thereby register with each other. To permit reciprocation of the movable plates, the movable block 50 at its opposite ends carries slides or cars 52 (Fig. 11) having rollers 53 thereon engageable with and adapted to roll along opposed parallel Walls of parallel horizontal slots 55 (Figs. 12 and 13). The latter are U-shaped in cross section and open inwardly toward each other from parallel guide bars 56 extending along and rigid with the horizontal frame members 47 which, for this purpose, project horizontally and forwardly from the front of the frame 49 The connection between the cam shaft 45 and the movable plates 42 includes a lever 58 which carries a follower 59 at one of its ends engageable with a barrel cam 61) (Fig. 9) fast on the cam shaft and which is pivoted intermediate its ends on a stub shaft 61 (Fig. 9) on the frame. At its other end, the lever is pivotally connected through a rod 62 to a horizontal rack bar 63 meshing with a spur gear 64 and slidable in bearings 65 (Figs. 9 and 13) carried by plates 40 which are secured as by bolts (not shown) to the forwardly projecting ends of the horizontal frame members 47. The spur gear is fast on a horizontal shaft 68 journaled at opposite ends in bearings 69 on the frame members 47 and having other gears 70 thereon meshing with teeth 71 formed along the bottom edges of the cars 52. Thus, during each revolution of the cam shaft 45, the cars are reciprocated between their advanced and retracted positions shown in Figs. 9 and respectively.

In the advancing movement of the movable plates 42, their free edges 51 engage laterally spaced portions of the suspended end portion 44 of the sheet 11 and force the same between the fixed plates 43 thereby drawing the upper end portion 73 and the suspended end portion of the sheet 11 vertically in opposite directions toward the plates. When the movable plates are in their advanced position (Fig. 10), the free edges 49 and 51 of the two sets of plates each lie along one of the parallel folds 15, the spacing between the latter being determined by the distance through which the free edges of the movable plates have moved horizontally past the free edges of the fixed plates.

To maintain positive control over the sheet 11 during the pleating operation and locate the ends 74 and 74:! thereof accurately with respect to the parallel folds 15, gripping elements 75 and 76 are provided on opposite sides of the path of movement of one of the sheet end portions 44 and 73 to engage the raised hem 77 thereon and limit its endwise movement to a position alongside the adjacent fold as shown in Fig. 10 while permitting edgewise movement of the end portion between them during the advance of the movable plates. In the present instance, one gripping element 75 is a stop engageable with the upper end portion 73 of the sheet to hold the same against the top surface of the uppermost movable plate 42 which is the other gripping element 76 and is disposed above the top fixed plate 43 to constitute a terminal plate of the two sets of plates.

The stop 75 shown in the drawings is a straight edge of an elongated weight 79 disposed above the fixed plates 43 and parallel to the free edges 49 thereof and pivotally supported on the horizontal guide bars 56 (Fig. 13) to swing about a horizontal axis toward and away from the fixed plates. An abutment surface 80 formed on a support 81 to be described later limits movement of the stop toward the plates to a position shown in Fig. 9 in which it is disposed in the path of the free edge 51 of the uppermost movable plate 42. This edge forces the upper end portion 73 of the sheet into engagement with the stop and is rounded to cam the latter upwardly where it may ride along the upper end portion of the sheet. Preferably, the stop is spaced inwardly from the free edge 51 of the uppermost plate a distance correlated with the length of the sheet and the horizontal spacing of the I 4 parallel folds 15 to space the sheet ends 74 and 74a horizontally from the folds and each other as shown in Fig. 10 and thereby reduce the thickness of the compact package 10 shown in Fig. 8.

To insure that the hem 77 on the upper end portion 73 of the sheet 11 will be drawn into engagement with the stop 75 during the pleating operation, the sheet is suspended in a predetermined position between the sets of plates 42 and 43 with a greater length of the sheet disposed below than is disposed above the plates as shown in Fig. 9 at the time that the movable plates are advanced into engagement with the sheet. While the sheet may be moved into and supported in such a predetermined position by hand, mechanism is provided to accomplish this automatically in timed relation to reciprocation of the movable plates 43. In the present instance, this mechanism comprises a conveyor or carrier 82 in the form of an endless belt (Fig. 9) disposed above the movable plates 42 in their retracted positions and having an upper horizontally disposed straight run 83 terminating at one end adjacent the vertical plane in which the sheet end portion 44 is to be suspended. The upper run 83 of the conveyor 82 parallels the direction of reciprocation of the movable plates 42 and encircles and is stretched between a rotatable idler roller (not shown) spaced forwardly from the frame and a driving roller 84 disposed above the retracted position of the movable plates and fast on a horizontal shaft 85 which is journaled at opposite ends in bearings 86 carried by the guide bars 56. A sprocket 87 carried by the driving roller shaft meshes with a chain 88 driven from the drive shaft 41 to rotate the driving roller in a clockwise direction as viewed in Fig. 9 and advance the upper straight conveyor run 83 horizontally toward and downwardly around the driving roller so that the leading end portion 44 of the sheet falls by gravity downwardly away from the conveyor. Preferably, a deflector bar 89 is positioned adjacent the driving roller to insure proper separation of the conveyor and the sheet and to guide the leading end portion of the latter in between the separated sets of plates.

When the sheet 11 is in its predetermined position with respect to the sets of plates 42 and 43 as described above at the time that the movable plates are advanced, a major length of the sheet is disposed below and suspended from the conveyor end with a short length of the trailing end portion 73 engaging and frictionally held by the conveyor as shown in Fig. 9. Such timing of the advance of the conveyor and the actuation of the pleating mechanism 17 is achieved in the present instance by placing the sheet on the upper straight run 83 of the conveyor in a position correlated with the relative speeds of the conveyor and the cam shaft 45 and the shape of the barrel cam 61}. This position is determined by trial and error and, once located, may be indicated by a transverse line marked on the conveyor at a point such as that indicated by the arrow at 91 in Fig. 9 to show the operator where to place the trailing end of the sheet.

Removal of the pleated strip 16 from the pleating mechanism 17 for the formation of the first transverse fold 20 is effected by the first folding mechanism 18 while the movable plates 42 are disposed in their advanced or overlapping position shown in Fig. 10. To permit such removal, the plates of both sets and the hem locating weight 79 are formed with narrow slots 92 (Figs. 10 and 11-) longer than the width of the pleated strip and extending inwardly from the free edges 49 and 51 of the plates in registry with each other to form a passage or groove 93 which lies in a vertical plane extending transversely of the pleated strip and is disposed along the path of the first blade 19 in registry with the line along which the fold 20 is to be formed. In its advancing movement, the blade is movable upwardly through the groove into engagement with an intermediate portion of the strip (see Fig. 2) to draw the opposite strip ends 30 and 30a along the plates and toward the groove and force the strip upwardly through the latter. To offset the ends 30 and 30a as described above and shown in Fig. 3, the groove 93 is offset slightly along the pleated strip from the longitudinal center thereof.

The first holder 35 which cooperates with the first blade 19 to form the fold "20 and also supports the shortened folded strip 21 preparatory to the formation of the second fold 24 is a part of the first folding mechanism 18 and comprises two parallel walls 94 defining between them an elongated recess 95 alined with the groove 93 engages and disposed adjacent and above the plates v42 and 43 to receive the strip 21 in the advance of the blade beyond the plates. In accordance with the invention, the walls are laterally spaced apart a proper distance to grip the strip frictionally and support the same during both the retraction of the first blade and the formation of the second fold 24. Herein, the walls are parts of the support 81 referred to above which is disposed rearwardly of the pleating mechanism 17 and comprises a plurality of folded plastic members 96 (Figs. 9 and 12) straddled by and secured as by bolts 97 to two vertical plates 98. The latter span and are mounted on the side walls of the frame 40.

The blade 19 in this instance is a thin flat generally rectangular plate (see Figs. 12 and 14) normally disposed below the pleating plates 42 and 43 in the vertical plane of the groove 93 and terminating at its upper end in a horizontal edge 100 which is longer than the width of the pleated strip 16 but is short enough to move upwardly between the support plates 98. To prevent the pleated strip from slipping along the blade and thereby maintain the strip in a proper position with respect to the parallel holder walls 94, the blade edge 100 is preferably serrated as shown. At its lower end, the blade is rigid with and supported by a slide 101 (Fig. 14 T-shaped in cross section and adapted to be received in and reciprocate along a correspondingly shaped recess extending vertically in a guidemember 102 (Fig. which is disposed below the plates and is mounted on a horizontally disposed crosspiece 103 spanning the side walls of the frame 40.

To reciprocate the first blade 19 vertically in timed relation to the reciprocation of the'movable pleating plates 42, its slide 101 thereof is connected to the cam shaft 45 through the medium of a lever 104 (Fig. 12) pivotally connected intermediate its ends to one end of a link 105 (Fig. 9) slidable vertically in a guide 106 on the frame and having afollower roller 107 at its other end engageable with a cam 108 fast on the cam shaft. One end of the lever 104 is pivoted on a lug projecting inwardly from one Wall of the frame and the other end is pivotally connected to another link 109 pivoted on the slide 101. A spring 110 stretched between the lever and a horizontal wall 111 at the bottom of the frame yieldably urges the blade into its lower inactive position shown in Fig. 12. The shape of the cam 108 and the lengths of the lever and the links are correlated with each other to raise the blade far enough to force the strip 16 completely beyond the pleating plates and into the recess 95 defined by the parallel walls 94. Initiation of the upward movement of the blade before retraction of the movable plates is made possible by forming the registering slots 92 in both the movable and the fixed plates.

To form the second fold 24, the parallel walls 94 of the holder 35 are formed'with horizontal slots 112 which register with the line of the second fold and through which the second blade 22 is movable edgewise in a horizontal direction. The second folding mechanism 23 is generally similar to the first mechanism 18 with one of the slots 112 constituting the inlet of a second recess 113 which is similar to the first recess 95 and defined by vertically spaced horizontal walls 114 of the second holder 36. To facilitate the formation of the second fold 24, a portion 115 of one of the horizontal walls 114 (see Fig. 12) of the second recess 113 at the inlet end 112 of the latter is yieldably urged as by a spring 116 toward the other wall to restrict the inlet opening of the resess but movable away from the other wall to permit the folded strip 21 to enter the recess 113 with its short end 26 lying alongside the longer end portion 27. The spring 116 is supported in a hole in one .of the plastic members 96 and is adjustable to vary the size of the inlet opening by turning a screw 117 (Fig. 9) threaded through one of the support plates 98.

The second blade 22 is generally rectangular and proiects rigidly in cantilever fashion from a car 119 (see Figs. 14 and 15) which is similar to the alternating plate cars 52 and is reciprocable horizontally in a hollow guide 120 of rectangular cross section secured as by bolts 121 to one of the support plates 98. To reciprocate the second blade, the ear is connected to a cam 122 fast on the cam shaft by a linkage including a bell crank 123 (Fig. 15) pivoted intermediate its ends on a boss 124 on a frame side wall and pivotally connected 'at one end to a link 125 which is slidable in a guide 126 (Fig. 9) on the frame and carries a roller 1 27 engageable with the cam. At its other end, the bell crank is pivotally connected through another link 128 (Fig. 15) to one end of a straight lever 129 pivoted intermediate its ends on the horizontal frame crosspiece 103 and projecting upwardly from the latter and through a slot in the guide 120 for connection with the car 119 through the medium of a link 130. The second blade is yieldably urged into its retracted position by a spring 131 stretched between the straight lever 129 and another side wall of the frame 40 The blade 28 of the third folding mechanism 29 (see Figs. 12, 14, and 15) is similar to the first blade 19 and is reciprocable in a vertical plane parallel to the latter back and forth from a position beneath the pleating plates 42 and 43 first toward and through a vertical passage 133 defined by registering slots 134 in the fixed plates and the hem locating weight 79. Then, the third blade advances into engagement with the folded strip 21 to fold the folded end portion 26 back upon the remainder 27 of the strip along the third transverse line 31 and force the strip out of the second recess 113 and the resulting doubled end portion 32 into a third recess 135. The latter is defined by horizontally spaced vertical walls 136 which at their lower ends provide an inlet slot 137 disposed adjacent and in registry with the third transverse line while the folded strip is supported in the second recess 113.

To reciprocate the third blade 28, a slide 138 (Fig. 14) supporting the same at its lower end is reciprocable in a vertical guide 139 (Fig. 15) secured to the frame crosspiece 1113 and is connected to the cam shaft 45 by a linkage similar .to that for the slide 101 of the first blade 19. This linkage includes a lever 140 which is pivoted at one end .on one frame side wall and pivotally connected at its other end to the slide 138 through the medium of a link 141 and intermediate its ends to an other link 142 having a follower roller 143 thereon engageable with a cam 144 (Fig. 9) on the cam shaft shaped to raise the third blade after retraction of the second blade 22 past the third transverse line. A spring 145 similar to the first pusher spring 110 yieldably urges the third pusher into its lower retracted position.

T o facilitate the formation of the third fold 31 and at the same time retain positive control over the folded strip 21 and avoid loosening of the second transverse fold 24, the invention contemplates bending the leading folded end portion 26 .of the strip out of a position of alinement with the second recess 113 shown in full in Fig. 12 and alongside the path of the third blade 28 into a position of alinement with the third recess 135 as shown in phantom in Fig. 14 whereby to initiate formation of the third fold while the folded strip is supported in the second recess and before the advance of the third blade. In the present instance, this is accomplished by the provision of a member 147 (Figs. 12 and 14) which is U-shaped in cross section and has opposed parallel walls or plates 148 defining a fourth recess 149 normally alined with the second recess 113 to form an extension of the latter disposed beyond the vertical plane of the third recess 135 and adapted to receive the leading end portion 26 of the folded strip 21 during the advance of the second blade. The member is disposed between the support plates 98 and at its open end, is fast on a horizontal shaft 150 (Figs. 9 and 14) journaled in a bearing 151 projecting from one of the support plates for swinging of the member about a horizontal axis disposed beyond the outlet end of the second recess and substantially along the line of intersection of the planes of the second and third recesses. To position the leading folded end of the folded strip properly in the U-shaped member, the stroke of the second blade is made long enough that, in its advancing movement, the blade pushes the leading strip end beyond the outlet end of the second recess and well into the fourth recess, the walls of the second recess being made shorter than the length of the twice folded strip to shorten the stroke of the second blade.

Swinging of the U-shaped member 147 which is a part of the holder 37 through a quarter revolution about its axis is effected in timed relation to the movements of the second and third blades 22 and 28 and after retraction of the second blade but before the advance of the third blade by a connection between the cam shaft 45 and the horizontal shaft 150 supporting the member. Herein,

this connection includes an arm 152 fast on the outer end of the member shaft and connected through a link 153 to one end of a lever 154 (Figs. 9 and 12) which is pivoted intermediate its ends on a wall of the frame and pivotally connected at its other end to a link 155 (Fig. 9). The latter is reciprocable in a guide 156 on the frame and carries a follower roller 157 at its lower end engageable with a cam 158 fast on the cam shaft. A spring 159 stretched between the arm 152 and the lowest intervening plate 46 yieldably urges the folding member into its normal horizontal position.

Folding of the strip 21 to bring the folds 2t) and 31 thereof together is effected in a manner similar to that for forming the third fold 31 by a second U-shaped folding member 161 (Figs. 12 and 14) adapted to receive the doubled end portion 32 of the strip in the advance of the third blade 28 beyond the outlet end of the third recess 135 and bend the same into a horizontal plane as shown in Fig. 12 alongside the path of a fourth blade 33 and in alinement with a fifth recess 162 defined by vertically spaced horizontal walls 163 on the support. The fourth blade is similar to the other blades previously described and is reciprocable horizontally from one side of the vertical plane of the third recess to force the folded strip out of the third recess and the second folding member and fold the same into the package which is forced edgewise into the fifth recess 162 where it is retained frictionally during retraction of the fourth blade. Holes 165 (see Fig. formed in the support plates 98 open horizontally into and are alined with the fifth recess for removal of the package 10 from this recess in an edgewise direction.

The mounting for the fourth blade 33 is similar to that of the second blade 22 and includes a car 166 (Figs. 9 and 15) reciprocable along a horizontal guide 167 and connected by a link 168 and a bell crank 169 to another link 170 which is reciprocable vertically in a guide 171 on the frame and carries a follower 172 engageable with a cam 173 on the cam shaft 45. A spring 174 (Fig. 15) is stretched between the linkage of the fourth blade and the lowermost fixed plate 46 to urge the car 166 and the blade yieldably into their retracted positions.

The second U-shaped member 161 is fast on an end of a shaft 176 (Figs. 9 and 15) which is journaled in a bearing 177 projecting from one of the support plates 98 and is parallel to the shaft 150 for the first folding member 147 at a point adjacent the intersection of the planes of the third and fifth recesses 135 and 162. An arm 178 fast on the outer end of the shaft 176 is connected through a link 179 and a lever 180 (Fig. 9) to another link 181 which is reciprocable vertically in a guide 182 on the frame and carries a follower 183 at its lower end engageable by a cam 184 on the cam shaft 45. A spring 185 similar to the spring 159 for the first folding member acts on the linkage for the second folding member 161 to urge the latter yieldably into its normal vertical position.

In the operation of the machine described above, let it be assumed that power is being applied to the shaft 41 to rotate the cam shaft 45 in a counterclockwise direction as viewed in Fig. 12 to actuate the various folding mechanisms and the driving roller 84 in a clockwise direction as viewed in Fig. 9 to advance the upper run 83 of the conveyor 82 toward and downwardly around the driving roller. Let it further be assumed that the cam shaft is in the position shown in Fig. 12 with the second U-shaped member 161 supporting the doubled end portion 32 of a folded strip 21 and disposed in its horizontal position and with the movable plates 42, all of the blades 19, 22, 28, and 33, and the first U-shaped member 147 disposed in their retracted positions and that another sheet 11 has been laid on the conveyor by the operator with its trailing end 74 in registry with the transverse line of the conveyor indicated at 91. As the cam shaft turns from this position, the fourth blade 33 is first advanced to force the strip 21 out from the third recess 135 and the second U-shaped member and into the fifth recess 162 and thereby complete the package 10. Then, the fourth blade is retracted to leave the package supported in the fifth recess from which it may be removed by hand.

During such actuation of the fourth blade 33, the leading end portion 44 of the sheet 11 laid on the conveyor is advanced by the latter toward and downwardly around the driving roller 84 Where it is engaged by the deflector 89 and guided into the vertical plane between the sets of pleating plates 42 and 43. At the time that the sheet reaches the position shown in Fig. 9 in which it is suspended from the conveyor 82 by its trailing end portion 73 with a greater length disposed below the lowermost fixed plate 46 than is disposed above the uppermost movable plate 42, the movable plates are advanced toward and into engagement with the sheet and between the fixed plates to thread the sheet back and forth zig-zag fashion around the adjacent plate edges 49 and 51 and thereby fold the sheet along the lines 15 and into the accordion pleated strip 16. In its advancing movement, the uppermost movable plate 42 moves the trailing end portion 73 of the sheet into engagement with and past the stop 75 until the latter engages the hem 77 thereon and limits its edgewise movement to the position shown in Fig. 10 in which the sheet ends 74 and 74a are spaced from the parallel folds 15 and from each other transversely of the pleated strip.

After the movable plates 42 have reached their advanced position shown in Fig. 10 in which they support the pleated strip 16 in a plane with the first transverse line 20 thereof in registry with the groove 93, the first blade 19 is advanced upwardly into engagement with the pleated strip and through the groove and the first slot to force the pleated strip out from between the plates and into the first recess and thereby fold the pleated strip lengthwise upon itself to form the folded strip 21. The movable plates 42 and the first blade are then retracted while the folded strip 21 is frictionally retained and supported by the parallel walls 94 in a position in which the second fold line 24 is disposed in registry with the horizontal slots 112 in the walls 94. Next, the second blade 22 is advanced and retracted to fold the folded strip lengthwise upon itself along the second transverse line 24 and leave the same supported in the second and fourth recesses 113 and 149 with the third transverse fold line 31 in registry with the inlet opening of the third recess in the space between the adjacent ends of the parallel walls 114 and plates 148 defining the second and fourth recesses.

Following the retraction of the second blade 22, the first U-shaped member 147 is swung from its vertical position of alinement with the second recess 113 shown in full in Fig. 12 through a quarter revolution to bend the leading end portion 26 of the folded strip 21 therein substantially at right angles to the second recess and into alinement with the third recess 135. The third blade 28 is then advanced upwardly through the space between the adjacent ends of the parallel walls 114 and the plates 148 to engage and fold the strip lengthwise upon itself along the third fold line 31 and force the strip out of the second and fourth recesses and into the third recess with the doubled end portion 32 of the strip disposed in the second U-shaped member 161. Then, the third blade 28 is lowered into its retracted position thereby leaving the folded strip supported in the second U-shaped member and the third recess with the final fold line registering with the inlet end of the fifth recess 162. Finally, the second U-shaped member is swung out of its vertical position and through a quarter of a revolution to bend the doubled end portion 32 at right angles to the remaining portion 27 of the strip and into alinement with the fifth recess as shown in Fig. 12 preparatory to the advance of the fourth blade 33 as described above to complete the S1liCCeSS10I1 of folding operations performed on the sheet From the foregoing, it will be apparent that positive control over each sheet presented to the machine is maintained during its progress through the successive folding mechanisms from the time that it is laid on the conveyor 82 until the time that it is removed from the fifth recess 162. Thus, the folds of each sheet are located accurately with respect to its edges to provide uniformity in the final package 10. Since the Walls defining each strip receiving recess, in addition to cooperating with the associated blade to form one fold in the strip, also support the latter in a proper position for the neXt succeeding folding operation, the machine arrangement is simple and compact and the necessity for other complicated supporting structure is avoided- The U-shaped members 147 and 161, by initiating the formation of the third fold 31 and the final fold, help prevent unfolding or loosening of the previously formed folds so that the latter are always tight in the final package 10.

We claim as our invention:

1. In a sheet folding machine, the combination of, mechanism for folding a flexible sheet along parallel lines to form an accordion pleated strip, means defining a slot disposed adjacent and extending transversely of said strip intermediate the ends thereof, means defining a parallel walled recess alined with said slot, a member mounted for endwise movement through said slot and into said recess to force a fold in said strip and leave the resulting folded strip frictionally supported between the walls of said recess, one wall of said recess having a slot extending transversely of said folded strip intermediate the ends of the latter, two parallel plates defining a second recess spaced from and alined with said second slot, a second member mounted for endwise movement through said second slot to force said folded strip through and beyond the second slot and thereby form a second fold therein while leaving the leading folded end portion of the strip supported between said plates, a support for the remaining portion of said folded strip disposed between said second slot and said second recess, means mounting said plates for rotation about a line extending transversely of said strip beyond the adjacent end of said support, means for rotating said plates to bend said leading end portion therein about said line and substantially normal to said remaining portion, means defining a third slot registering with said line, a third member mounted for endwise movement through said third slot alongside said bent end portion to force said strip through the third slot and form a third fold along said line while removing the opposite end portions of the strip from said second recess and said support, and power actuated means connected to said mechanism, said members, and said plates and operable to actuate the same in timed relation first to accordion pleat said strip, next to advance and retract said first member, then to advance and retract said second member, next to rotate said plates and bend said leading end portion, and finally to advance and retract said third member.

2. In a sheet folding machine, the combination of, mechanism for folding a flexible sheet along parallel lines to form an accordion pleated strip, means defining a slot disposed adjacent and extending transversely of said strip intermediate the ends thereof, means defining a parallel Walled recess alined with said slot, a member mounted for endwise movement through said slot and into said recess to force a fold in said strip and leave the resulting folded strip frictionally supported between the walls of said recess, one wall of said recess having a slot extending transversely of said folded strip intermediate the ends of the latter, two parallel plates defining a second recess spaced from and alined with said second slot, a second member mounted for endwise movement through said second slot to force said folded strip through and beyond the second slot and thereby form a second fold therein while leaving the leading folded end portion of' the strip supported between said plates, a support for the remaining portion of said folded strip disposed between said second slot and said second recess, means mounting said plates for rotation about a line extending transversely of said strip beyond the adjacent end of said support, means for rotating said plates to bend said leading end portion therein about said line and substantially normal to said remaining portion, means defining a third slot registering with said line, and a third member mounted for endwise movement through said third slot alongside said bent end portion to force said strip through the third slot and form a third fold along said line while removing the opposite end portions of the strips from said second recess and said support.

3. In a sheet folding machine, the combination of, a pleating mechanism operable to fold a flexible sheet along spaced parallel lines and into an accordion pleated strip and leave the latter supported in a plane, a first folding mechanism including a member projectable edgewise into engagement with said pleated strip to remove the latter from said pleating mechanism and fold the same along a transverse line intermediate the strip ends while leaving the resulting folded strip supported in a second plane including the line and disposed substantially perpendicular to the pleated strip, a second folding mechanism including a second member projectable edgewise into engagement with said folded strip to remove the latter from said first folding mechanism and fold the same along a second transverse line intermediate its ends while 5O between the adjacent pleats whereby to fold the sheet leaving the strip supported in a third plane including the second line and disposed substantially normal to said second plane, and a third folding mechanism including means supporting oneend portion of said strip in said third plane and mounted for rotation about an axis extending longitudinally of and disposed adjacent a third transverse line of said strip to bend the end portion along the third line out of the third plane and alongside a fourth plane normal to the latter, said third folding mechanism also including a third member projectable edgewise in said fourth plane and alongside said bent end portion into engagement with said strip to fold the latter along said third line and remove the same from said second folding mechanism and said supporting means after the latter has been swung about said axis to bend said end portion out of said third plane.

4. Mechanism for folding a flexible sheet into an accordion pleated strip comprising a carrier for supporting said sheet and advancing the same to suspend the leading edge portion in a vertical plane beyond one end of the carrier, a plurality of vertically spaced horizontal plates divided into two sets mounted in staggered relation on opposite sides of said plane with one set disposed beneath the carrier, means actuated in timed relation to the advance of said carrier and after movement of a longer length of said sheet below the lowermost one of said plates than the length of the sheet disposed above the uppermost plate and operable to move the plates of said sets relative to and toward each other into overlapping relation While leaving the sheet threaded back and forth zig-zag fashion between the plates to form an accordion pleated strip, and a stop positioned adjacent the path of travel of said sheet and mounted for movement toward and away from said path, said stop automatically engaging said length of said sheet disposed above said plates and operable by engagement with the hem on the trailing edge of the sheet'to limit movement of the hem to a predetermined position relative to the folds of said strip.

5. In a machine for foldinga flexible sheet while the latter is suspended in a predetermined position in a vertical plane, the combination of, a stationary support, a plurality of vertically spaced horizontal plates mounted on said support and divided into two sets disposed in staggered relation on opposite sides of said plane, means for relatively moving said sets edgewise across said plane and past each other into overlapping relation to draw the opposite end portions of the sheet vertically toward each other and thread the sheet zig-zag fashion back and forth into an accordion pleated strip, and a member freely pivoted on said support above the uppermost one of said plates to turn about a horizontal axis and having a weighted arm swinging downwardly by gravity to engage the upper end portion of said sheet and to press and hold the same against said uppermost plate during the pleating operation, said arm providing an abutment engageable with the hem of the sheet to limit edgewise advance of the hem.

6. In a'mechanism for folding a flexible sheet while one portion of the latter is supported in a predetermined plane, the combination of, a stationary support, a plurality of laterally spaced parallel plates extending normal to said plane and divided into two sets disposed in staggered relation on opposite sides of the plane and said sheet portion, means mounting said sets on said support for relative movement edgewise across said plane and past each other into overlapping relation to draw opposite end portions of said sheet toward each other longitudinally of the plane as the sheet becomes threaded back and forth between the plates to form an accordion pleated strip, and a freely swinging stop pivoted on said support to swing by gravity toward the terminal plate of one of said sets and into engagement with one of said end portions during the pleating operation and press and hold the end portion against said terminal plate, said stop providing an abutment to engage the hem of the end portion to limit edgewise advance thereof to a position alongside the adjacent fold of said pleated strip.

7. In a mechanism for folding a flexible sheet while one portion of the latter is supported in a predetermined plane, the combination of, a plurality of laterally spaced parallel plates extending normal to said plane and divided into two sets mounted in staggered relation on opposite sides of the plane and said sheet portion, means for rela- 'tively moving said sets edgewise across said plane and past each other into overlapping relation to draw opposite end portions of said sheet toward each other longitudinally of the plane as the sheet becomes threaded back and forth between the plates to form an accordion pleated strip, and two gripping members disposed on opposite sides of the path of one of said end portions and operable during the pleating operation to hold and press the end portion between them while permitting the end portion to slip between the members as said two sets of plates move together, one of said members providing an abutment engageable with the hem of the end portion to limit the advance of the end portion and position the hem alongside the adjacent fold of said pleated strip.

8. In a mechanism for folding a flexible sheet While one portion of the latter is supported in a predetermined position in a plane, the combination of, a plurality of laterally spaced parallel plates extending normal to said plane and divided into two sets disposed in staggered relation on opposite sides of said plane and relatively movable edgewise across said plane past each other and into overlapping positions to thread said sheet back and forth between adjacent plates and thereby fold the sheet into an accordion pleated strip, and a stop disposed adjacent the terminal plate of one of said sets and frictionally engageable with one of the end portions of said sheet automatically as an incident to the pleating operation while permitting advance of the end portion past the stop as said two sets of plates move together, said stop providing an abutment engageable with the hem of the end portion to limit edgewise movement of the hem to a predetermined position relative to the folds of said pleated strip.

9. In a strip folding mechanism, the combination of, a pair of laterally spaced parallel Walls defining between them a passage open at oppositie ends, means for supporting a flexible strip with the line along which the strip is to be folded disposed adjacent and in registry with one of said passage ends, a blade mounted for edgewise reciprocation through said passage end and between said walls to fold said strip lengthwise upon itself along said line and force the strip in its folded condition between said walls with its leading folded end portion disposed beyond the second end of said passage, a pair of parallel plates disposed beyond said other passage end to receive said folded end portion of said strip in the advance of the blade and frictionally retain the same during retraction of the blade, a second pair of laterally spaced parallel walls defining a second passage disposed on one side of said first passage and lying in a plane extending normal to the latter and crosswise of said strip, the adjacent ends of one of said first walls and one of said plates being spaced apart on opposite sides of said plane to define the inlet opening of said second passage,

means rotatably supporting said plates to '"bend said folded end portion out of alinement with the other end portion of said strip and alongside said plane on the other side of said first passage into alinement with said second passage, a second blade mounted for edgewise reciprocation in said plane, and means actuated in timed relation to swinging of said plates and after said folded end portion has been positioned alongside said plane and operable to advance said second blade endwise alongside the folded end portion and through said inlet opening to force said strip through the latter and into said second passage and withdraw the opposite end portions of the strip from between said walls and said plates.

10. In a strip folding mechanism the combination of, two laterally spaced walls adapted to support one end portion of a flexible strip, two laterally spaced parallel plates adapted to support the other end portion of said strip in ahnement with said first end portion, the adjacent edges of one of said walls and the corresponding one of said plates being spaced apart to define a lateral opening between the walls and the plates extending crosswise of said strip, a blade movable edgewise in a path extending substantially normal to said strip and through said openmg, means for advancing said blade from one side of said strip and through said opening to fold the strip lengthwise upon itself and withdraw said end portions from between said walls and said plates, means support- 1ng sa1d plates to swing about an axis extending longitudlnally of said opening and beyond said Wall end, and means operated before said blade is advanced to swing said plates about said axis way from said strip side and bend said other end portion at right angles to said first end portion and into a position alongside said path.

11. In a strip folding mechanism, the combination of, a wall having a slot therein longer than the width of a fiexlble strip to be folded, means for supporting one end portion of said strip in a plane against said wall with the line along which the strip is to be folded registering wlth said slot and disposed in a second plane substantially normal to said first plane, a pair of laterally spaced parallel plates adapted to support the other end portion of said strip between them in said first plane, means mounting said plates to swing about an axis extending longitudinally of said slot and bend said other end portion of said strip out of said first plane away from one side'thereof and into a position alongside said second plane, a blade movable in said second plane and through said slot, and means for advancing said blade edgewise from said side of said first plane and alongside said other end portion to engage said strip along said line and force the strip through said slot and the other end portion out from between said plates whereby to fold the strip longitudinally upon itself.

References Cited in the file of this patent UNITEDSTATES PATENTS 7,722 Snow Oct. 15, 1850 27,392 Snow Mar. 6, 1860 300,606 Hellmuth June 17, 1884 1,201,719 Grotf Oct. 17, 1916 1,237,514 Heaney Aug. 21, 1917 1,436,005 Barggren Nov. 21, 1922 1,571,105 Burdick Jan. 26, 1926 2,082,243 David et al. June 1, 1937 2,183,497 Turner Dec. 12, 1939 2,308,155 Clegg Jan. 12, 1943 FOREIGN PATENTS 106,186 Great Britain Ma 17, 1917 130,950 Germany Mar 16, 1901 

